JP5628728B2 - Motor control device and vehicle seat device - Google Patents

Description

  The present invention relates to a motor control device and a vehicle seat device.

  A movable part is provided in a vehicle seat, an electric door mirror, a power window, and the like, and the movable part is driven by a motor. In order to accurately control the position and speed of the movable part by the control device, it is necessary to detect the rotation amount and position of the motor in operation. A sensor is used to detect the rotation amount and position of the motor. That is, a sensor (for example, a hall element, an encoder, a reed switch sensor) is provided in a motor or the like, a signal synchronized with the rotation of the motor in operation is output by the sensor, and the output signal of the sensor is detected by a detection circuit (for example, a comparator or It is input to the control device via the AD converter.

  However, using a sensor increases the cost. In view of this, a technique has been proposed in which the motor rotation signal and position are detected by a circuit subsequent to the motor using a motor current signal without using a sensor (see, for example, Patent Document 1 and Patent Document 2). When the motor is operating, the current signal of the motor includes a direct current component, a low frequency component, a high frequency noise, and the like, and further, a pulsation synchronized with the rotation of the motor (hereinafter referred to as ripple). ) Ingredients are also included. In the techniques described in Patent Document 1 and Patent Document 2, a ripple component is extracted by processing a current signal of a motor by a subsequent circuit. Specifically, a DC component, a low frequency component, and a high frequency noise are removed from the motor current signal by a filter in the subsequent circuit, and the ripple component is passed. Since the frequency of each component of the motor current signal fluctuates due to environmental changes, a switched capacitor filter capable of varying the cut-off frequency is used as the filter of the subsequent circuit. Specifically, a signal that has passed through the switched capacitor filter is fed back to the arithmetic circuit, and the arithmetic circuit calculates a cutoff frequency from the feedback signal to set the cutoff frequency of the switched capacitor filter.

  In the technique described in Patent Document 1, the ripple pulse shaping circuit pulses the ripple component that has passed through the switched capacitor filter (SCF), and the counter (CT) counts the number of pulses of the output signal of the ripple pulse shaping circuit. . The number of pulses counted by the counter (CT) corresponds to the amount of rotation of the motor and the amount of movement of the movable part.

By the way, a movable range is set for the movable portion, and the movable portion can move from one end of the movable range to the other end. Patent Document 3 discloses a technique for stopping a motor when a movable portion driven by the motor moves to the end (X) of the movable range (A). Specifically, the lock detection area (l ₁₁ ) is set inside the end (X) of the movable range (A) of the movable part (see FIG. 7 in Patent Document 3). When the movable part enters the lock detection area (l ₁₁ ) from outside the lock detection area (l ₁₁ ) due to the rotation of the motor, the movable part moves to the end (X) of the movable range (A). The locked state determination unit (73) of the control unit (22) detects the lock of the movable unit by the motor current, and the stop position information correction unit (84) of the control unit (22) 22), the output of the motor is stopped (see FIG. 8 of Patent Document 3). Thereafter, the current position information update unit (75) of the control unit (22) stores the value of the current position information calculated by the current position information calculation unit (77) in the lock position information storage unit (78). Update to information value. The lock position information represents the end (X) of the movable range (A) of the movable part.

Japanese Patent Laid-Open No. 2003-9585 JP 2008-283762 A Special Table 2010-33513

  However, a transmission mechanism such as a gear is provided between the motor and the movable part, and the transmission mechanism includes play and rattling. Therefore, even if the movable part moves to the end of the movable range and is locked, the motor can further rotate. The technique of Patent Document 3 does not consider that the movable part is locked and the motor further rotates, and the current position information updated to the value of the lock position information accurately represents the actual position of the movable part. It was n’t. In other words, after the movable part moves to the end of the movable range and the motor stops, when the motor is rotated in the reverse direction, only the motor rotates immediately after the motor rotates, but the movable part does not move. The current position information is shifted from the actual position of the movable part.

  Further, even if the movable part moves to the end of the movable range and is locked and the motor further rotates, the rotation speed of the motor is extremely low, so that the ripple pulse is not generated accurately. Therefore, when the movable part moves to the end of the movable range and is locked and the motor further rotates, the position of the motor cannot be obtained accurately.

  Therefore, the problem to be solved by the present invention is to make it possible to accurately obtain the position of the motor even when the movable part moves to the end of the movable range and is locked and the motor further rotates. is there.

According to the invention according to claim 1 for solving the above problems,
The motor controller drives a movable part that can move between both ends of the movable range, and when operated, extracts a ripple component from the current signal of the motor that generates a periodic ripple in the current signal, An extraction circuit that outputs a pulse signal in which the ripple component is pulsed, a current detection unit that detects the current of the motor, and data of the current detected by the current detection unit and the pulse signal are input, A control unit for controlling the motor; initial position data representing an initial position of the motor before operation by a pulse number from the initial position to a predetermined origin position; and the movable unit from the movable range to the end. Constraint start position data representing the constraint start position of the motor that can move and further rotate by the number of pulses from the constraint start position to the origin position Lock position data representing the lock position of the motor, which is restrained without the motor being able to rotate any more, with the movable part positioned at the end of the movable range, in terms of the number of pulses from the lock position to the origin position Each time a pulse of the pulse signal is input after the start-up process, and the control unit generates the pulse signal after the start-up process. Counting the number of pulses counted, adding the counted number of pulses to the value of the initial position data, or subtracting the counted number of pulses from the value of the initial position data, and calculating in the counting process after the start-up process A determination process for determining whether or not the position of the motor is between the constraint start positions by comparing the difference or the sum with the value of the constraint start position data; and When the determination process determines that the position of the motor is not between the constraint start positions, the rotation of the motor is continued until the current data input from the current detection unit exceeds a predetermined value, and the current detection unit A stop process for stopping the motor when the current data input from the input data exceeds a predetermined value, and an update process for rewriting the initial position data stored in the storage unit to the value of the lock position data after the stop process, Is further executed.

According to the invention of claim 2, in claim 1,
A second determination process for determining whether the value of the initial position data is equal to the value of the lock position data; and the control unit determines whether the value of the initial position data is equal to the value of the lock position data. And a prohibiting process for prohibiting the motor from stopping until the difference or sum calculated in the counting process after execution of the starting process becomes equal to the value of the constraint start position data. Run.

According to the invention of claim 3, in claim 1 or 2,
The control unit further executes a second stop process for stopping the motor when the determination process determines that the position of the motor is between the constraint start positions.

According to the invention of claim 4, in claim 2,
When the control unit determines in the second determination process that the value of the initial position data is not equal to the value of the lock position data, the activation process is executed.

According to the invention of claim 5, in any one of claims 1 to 4,
The control unit executes the determination process when a predetermined stop condition is satisfied after the activation process.

According to the invention of claim 6,
A vehicle seat device includes the motor control device according to any one of claims 1 to 5 and a seat body having the movable portion driven by the motor.

According to the first aspect of the present invention, the initial position, the constraint start position, and the lock position are defined by the coordinate system representing the motor position, and the initial position data, the constraint start position data, and the lock position data indicate the motor position as the number of pulses. Therefore, the processing can be performed using a coordinate system in which the control unit expresses the position of the motor. Therefore, the difference or sum calculated by the control unit in the counting process accurately represents the actual motor position, and the determination process can accurately determine whether the motor position is between the constraint start positions. it can.
When the control unit determines that the position of the motor is not between the restraint start positions, the movable unit is moved and locked to the end of the movable range, and the control unit continues to rotate the motor thereafter. When the play or rattling of the transmission mechanism between the motor and the movable portion is tightened, the load on the motor increases and the motor current increases. At this time, since the control unit stops the motor when the current data input from the current detection unit exceeds a predetermined value, the motor is stopped in a locked state at the lock position. Thereafter, since the initial position data is rewritten to the number of pulses that is the value of the lock position data representing the lock position, the initial position data accurately represents the actual lock position of the motor. Therefore, even when the movable part moves to the end of the movable range and is locked and the motor further rotates, the position of the motor is accurately calculated.
Even if the movable part moves to the end of the movable range and is locked, and the motor further rotates, even if the ripple pulse is not generated accurately, the initial position data is the lock position data indicating the lock position after the stop process. Since the value is rewritten, the position of the motor is accurately calculated even during the subsequent operation of the motor. That is, even if a cumulative error occurs in the motor position calculated by the control unit, the error is eliminated.

  According to the invention of claim 2, when the control unit determines in the second determination process that the value of the initial position data is equal to the value of the lock position data, the initial position before the operation of the motor is the lock position. In that case, since the motor is prohibited to stop until the difference or sum calculated in the counting process is equal to the value of the constraint start position data, the motor must stop between the lock position and the constraint start position. There is no. Therefore, the motor position calculated by the control unit accurately represents the actual motor position. Therefore, the position of the motor can be accurately controlled.

  According to the invention of claim 3, when the control unit determines that the position of the motor calculated by the control unit is between the constraint start positions, the control unit stops the motor. Between the restraint start positions. Therefore, the position of the motor calculated by the control unit when the control unit subsequently starts up the motor accurately represents the actual position of the motor. Therefore, the position of the motor can be accurately controlled.

  According to the invention of claim 5, even if a predetermined stop condition is satisfied, the control unit executes the determination process, and if the control unit executes the stop process as a result of the determination, the motor continues to rotate. After that, the motor stops. That is, when the position of the motor is between the restraint start position and the lock position, even if a predetermined stop condition is satisfied, the motor does not stop immediately but stops at the lock position.

It is the block diagram which showed the motor control apparatus which concerns on embodiment to which this invention is applied. It is the figure which showed the coordinate system expressing the position of a motor, and the coordinate system expressing the position of a movable part. It is a timing chart showing a waveform of a motor current signal. It is a timing chart showing a waveform of a motor current signal. It is the figure which showed the waveform of the input signal and output signal of a current-voltage converter, a high pass filter, a band pass filter, a filter and a differential amplifier, an amplifier, and a waveform shaping part. It is the graph which showed the frequency characteristic of the filter. It is a circuit diagram showing a filter and a differential amplifier. It is the timing chart which showed the waveform of the input signal and output signal of a filter and a differential amplifier. It is the flowchart which showed the flow of the process which starts a motor. It is the flowchart which showed the flow of the process which counts the pulse number of a pulse signal during operation | movement of a motor. It is the flowchart which showed the flow of the process which stops a motor. It is the side view which showed the seat main body of the vehicle seat apparatus. It is the graph which showed the frequency characteristic of the filter. It is the graph which showed the frequency characteristic of the filter.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. However, the embodiments described below are given various technically preferable limitations for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

FIG. 1 is a block diagram of the motor control device 1.
The motor control device 1 includes a motor 2, an extraction circuit 3, a control unit 4, a storage unit 5, a motor driver 6, an A / D converter 7, an A / D converter 8, an input unit 9c, and the like.

  A transmission mechanism is provided between the motor 2 and the movable part, the motor 2 is coupled to the transmission mechanism, and the transmission mechanism is coupled to the movable part. When the motor 2 rotates, the power of the motor 2 is transmitted to the movable part by the transmission mechanism, and the motor 2 moves the movable part. FIG. 2 is a diagram showing a coordinate system expressing the position of the motor 2 and a coordinate system expressing the position of the movable part 99. Stoppers 98 and 98 are respectively provided at both ends of the movable range of the movable portion 99, and the movable range of the movable portion 99 is set between these stoppers 98 and 98. When the motor 2 rotates forward and the movable part 99 comes into contact with one of the stoppers 98, the movable part 99 cannot move out of the movable range, but the motor 2 is free from play of the transmission mechanism, elastic deformation, rattling, etc. You can rotate forward by the minute. On the other hand, when the motor 2 rotates forward and the movable part 99 comes into contact with the other stopper 98, the movable part 99 cannot move out of the movable range, but the motor 2 is free from play, elastic deformation and rattling of the transmission mechanism. It can be reversed by the same amount. That is, the movable range of the motor 2 is wider than the movable range of the movable portion 99.

  The position where the movable portion 99 moves from the movable range until it abuts against the stopper 98 and the play of the transmission mechanism or the like starts to be tightened by the further rotation of the motor 2 is referred to as a constraint start position. That is, if the position of the motor 2 is the restraint start position, the movable part 99 is positioned at the end of the movable range and abuts against the stopper 98 to restrain the movable part 99, but the movable part 99 moves toward the stopper 98. The motor 2 can further rotate in the direction.

  A position where the play of the transmission mechanism or the like is tightened while the movable portion 99 is in contact with the stopper 98 and the motor 2 cannot be rotated any more and is restrained is called a lock position. The positions at both ends of the movable range of the motor 2 are the lock positions. That is, if the position of the motor 2 is the lock position, the movable portion 99 is positioned at the end of the movable range and abuts against the stopper 98, there is no play or the like of the transmission mechanism, and the movable portion 99 faces the stopper 98. The motor 2 cannot rotate in the direction.

  A range from the constraint start position to the lock position is referred to as a constraint range, and a range from one constraint start position to the other constraint start position is referred to as a non-constraint range. Further, a predetermined origin position is set in advance between both of the constraint start positions, and the position of the motor 2 is determined with the origin position as a reference. The origin position may be set as the lock position.

  The motor 2 is a direct current motor. When a current flows through the motor 2, the motor 2 rotates and the motor 2 generates a periodic ripple in the current. The current signal of the motor 2 will be described with reference to FIGS. FIG. 4 is a chart showing changes in the level of current flowing through the motor 2 when the motor 2 is driven from a certain position within the movable range to the locked position. FIG. 4 is a chart showing an enlarged time and current scale in the A part shown in FIG.

  In FIG. 3, time T1 is timing when the motor 2 is started, and time T2 is timing when the motor 2 starts to operate stably. Time T3 is a timing when the movable portion 99 driven by the motor 2 comes into contact with the stopper 98 and the transmission mechanism that transmits the power of the motor 2 to the movable portion 99 starts to be tightened. Time T3 is also the timing at which the motor 2 is positioned at the restraint start position. Time T4 is a timing at which the motor 2 stops when the position of the motor 2 becomes the locked position.

  As shown in FIGS. 3 and 4, the current signal of the motor 2 includes a DC component, a ripple component, and one or more frequency components (AC component), and the frequency component and the ripple component are superimposed on the DC component. Of the current signal of the motor 2, the high frequency component in which the current level has changed abruptly is noise (see, for example, symbol n). Note that FIG. 4 is illustrated as having no high frequency noise component.

  In a period P1 from time T1 to time T2, the ripple component r1 and a low frequency component having a frequency lower than the ripple component r1 are superimposed on the direct current component. Immediately after the start of the motor 2 in the period P1, the current level of the low frequency component is large due to the influence of the inertial force, and then the current level of the low frequency component gradually decreases with time. Immediately after the start of the motor 2, the amplitude of the ripple component r1 having a higher frequency than the low frequency component is large, and thereafter, the frequency of the ripple component r1 gradually increases with time, and the amplitude of the ripple component r1 is increased over time. It gradually decreases with the progress of.

  In the period P2 from time T2 to time T3, the ripple component r2 and the low frequency component having a frequency lower than the ripple component r2 are superimposed on the DC component, the DC component is substantially constant and stable, and the frequency of the low frequency component and The amplitude is stable, and the frequency and amplitude of the ripple component r2 are stable. The reason why the frequency of the ripple component r2 is higher than the frequency of the low frequency component is that a plurality of coils built in the motor 2 have a difference in winding resistance.

  In a period P3 from time T3 to time T4, the frequency of the low frequency component of the current signal of the motor 2 decreases, and the current level of the low frequency component gradually increases with time. In the period P3, the frequency of the ripple component r3 in the current signal of the motor 2 gradually decreases with time, and the amplitude of the ripple component r3 gradually increases with time. In the period P3, since the movable part 99 is in contact with the stopper 98, the motor 2 rotates at an extremely low speed.

  The frequency and amplitude of the low frequency component and the ripple component of the current signal of the motor 2 are affected by various environments (for example, load on the motor 2, environmental temperature, power supply voltage of the motor 2, etc.). Therefore, when the environment changes, the frequency and amplitude of the low frequency component and the ripple component change.

  The extraction circuit 3 extracts a ripple component from the current signal of the motor 2 as described above, pulses the ripple component, and outputs a pulse signal obtained by pulsing the ripple component to the control unit 4. The ripple extraction method using the extraction circuit 3 and the extraction circuit 3 will be specifically described.

  As shown in FIG. 1, the extraction circuit 3 includes a current-voltage converter 10, a high-pass filter 20, a band-pass filter 30, a filter 40, a differential amplifier 50, an amplifier 60, and A waveform shaping unit 70 is provided. FIG. 5 is a diagram for explaining input signals and output signals of the current-voltage converter 10, the high-pass filter 20, the band-pass filter 30, the filter 40 and the differential amplifier 50, the amplifier 60, and the waveform shaping unit 70. In FIG. 5, the period in which the input signals and output signals of the current-voltage converter 10, the high-pass filter 20, and the band-pass filter 30 are shown is from time T1 to the beginning of the period P2 in FIG. A period in which the input signals and output signals of the filter 40, the differential amplifier 50, the amplifier 60, and the waveform shaping unit 70 are shown is a part of the period P2 in FIG.

  The current / voltage converter 10 inputs a current signal of the motor 2. The current-voltage converter 10 converts the input current signal of the motor 2 into a voltage signal. Specifically, the current-voltage converter 10 includes a resistor 11, the resistor 11 is connected between the ground and the motor 2, and the current signal of the motor 2 is converted into a voltage signal between the resistor 11 and the motor 2. Converted. The current-voltage converter 10 outputs the converted voltage signal to the filter 40 and the differential amplifier 50 via the high-pass filter 20 and the band-pass filter 30. The current-voltage converter 10 may be one using an operational amplifier (for example, a negative feedback current-voltage converter).

The high-pass filter 20 receives the voltage signal converted by the current-voltage converter 10 (output signal of the current-voltage converter 10). The high-pass filter 20 passes a high-frequency component of the voltage signal converted by the current-voltage converter 10 (an output signal of the current-voltage converter 10) and attenuates a low-frequency component. That is, the high pass filter 20 removes a DC component from the voltage signal converted by the current-voltage converter 10. The high pass filter 20 outputs a signal with the low frequency component attenuated to the filter 40 and the differential amplifier 50 via the band pass filter 30.
The high-pass filter 20 is one using an operational amplifier (for example, a negative feedback high-pass filter or a positive feedback high-pass filter) or one using a resistor / capacitor (for example, a CR high-pass filter).

The bandpass filter 30 inputs the voltage signal converted by the current-voltage converter 10 via the highpass filter 20. The band-pass filter 30 passes a component in a predetermined frequency band of the voltage signal (the output signal of the high-pass filter 20) converted by the current-voltage converter 10, and attenuates a component outside the predetermined frequency band. That is, the band-pass filter 30 removes high-frequency noise components from the voltage signal (output signal of the high-pass filter 20) converted by the current-voltage converter 10, and removes low-frequency components that could not be removed by the high-pass filter 20. Remove. The bandpass filter 30 outputs a signal obtained by attenuating a component outside a predetermined frequency band to the filter 40 and the differential amplifier 50.
The band pass filter 30 uses an operational amplifier (for example, a multiple negative feedback type band pass filter, a multiple positive feedback type band pass filter) or a resistor / capacitor.

  Although the band pass filter 30 is provided in the subsequent stage of the high pass filter 20, the band pass filter 30 may be provided in the subsequent stage of the current-voltage converter 10 and in front of the high pass filter 20.

  The filter 40 receives the voltage signal converted by the current-voltage converter 10 through the high-pass filter 20 and the band-pass filter 30, and filters the signal. The filter 40 outputs the filtered signal to the differential amplifier 50.

FIG. 6 is a graph showing the frequency characteristics of the filter 40.
As shown in FIG. 6, the filter 40 is a bandpass filter. The filter 40 passes the component in the intermediate frequency band between the low cutoff frequency fc1 and the high cutoff frequency fc2 in the voltage signal (the output signal of the bandpass filter 30) converted by the current-voltage converter 10. . The low cut-off frequency fc1 is the cut-off frequency of the high-pass filter portion of the filter 40, and the high cut-off frequency fc2 is the cut-off frequency of the low-pass filter portion of the filter 40, and the low cut-off frequency fc1 <the high cut-off frequency fc2. is there. The cut-off frequency refers to a frequency at which the output power is 1/2 of the input power. That is, the frequency at which the gain G is −3 db is the cutoff frequency.

  Further, the filter 40 attenuates a component in a low frequency range lower than the low cutoff frequency fc1 in the voltage signal (the output signal of the bandpass filter 30) converted by the current-voltage converter 10. Specifically, in the low frequency range lower than the low cut-off frequency fc1, the filter 40 has a lower component frequency included in the voltage signal (the output signal of the bandpass filter 30) converted by the current-voltage converter 10. The low frequency band component of the voltage signal (the output signal of the band pass filter 30) converted by the current-voltage converter 10 is attenuated so that the attenuation rate becomes higher.

  Further, the filter 40 attenuates a component in a high frequency region exceeding the high cut-off frequency fc2 in the voltage signal (the output signal of the bandpass filter 30) converted by the current-voltage converter 10. Specifically, in a high frequency region exceeding the high cut-off frequency fc2, the filter 40 attenuates as the frequency of the component included in the voltage signal (the output signal of the bandpass filter 30) converted by the current-voltage converter 10 decreases. The high frequency component of the voltage signal (the output signal of the bandpass filter 30) converted by the current-voltage converter 10 is attenuated so that the rate becomes lower.

  As shown in FIGS. 3 and 4, the current signal of the motor 2 is obtained by superimposing a ripple component and a low-frequency component having a frequency lower than that of the ripple component. The frequency of the ripple component is checked in advance by experiments, measurements, etc., and in the circuit design of the filter 40, the high cutoff frequency fc2 of the filter 40 is set to the frequency of the ripple component (for example, the frequency of the ripple component due to temperature change). , The frequency at room temperature). Therefore, the filter 40 has a ripple component in the voltage signal (the output signal of the band pass filter 30) converted by the current-voltage converter 10 that is lower in frequency than the low frequency component (the frequency of the low frequency component is lower than that of the ripple component). Attenuate with high attenuation factor. That is, the filter 40 removes the ripple component more efficiently than the low frequency component. Therefore, the filter 40 outputs a signal from which the ripple component has been removed to the differential amplifier 50.

  The differential amplifier 50 inputs the voltage signal converted by the current-voltage converter 10 via the high-pass filter 20 and the band-pass filter 30 and also receives the output signal of the filter 40. The differential amplifier 50 takes the difference between the input output signal of the filter 40 and the voltage signal converted by the current-voltage converter 10 (the output signal of the bandpass filter 30), and amplifies the difference. The differential amplifier 50 outputs a differential signal representing the difference to the amplifier 60.

  FIG. 7 is a circuit diagram illustrating an example of the filter 40 and the differential amplifier 50. FIG. 8A is a timing chart showing the waveform of the voltage signal in the portion A shown in FIG. 7, and FIG. 8B is a timing showing the waveform of the voltage signal in the portion B shown in FIG. FIG. 8C is a timing chart showing the waveform of the voltage signal in the portion C shown in FIG.

  As shown in FIG. 7, the filter 40 includes a high-pass filter 41, a low-pass filter 42, and a high-pass filter 43. The output of the band pass filter 30 is connected to the input of the high pass filter 41, the output of the high pass filter 41 is connected to the input of the low pass filter 42, and the output of the low pass filter 42 is connected to the input of the high pass filter 43.

  The high pass filter 41 is a secondary CR high pass filter. That is, the high pass filter 41 includes a capacitor 41a, a resistor 41b, a capacitor 41c, and a resistor 41d. Note that the high-pass filter 41 may be a primary CR high-pass filter including one capacitor and a resistor. Further, the high-pass filter 41 may be a third-order or higher CR high-pass filter.

The low pass filter 42 is a secondary RC low pass filter. That is, the low-pass filter 42 includes a resistor 42a, a capacitor 42b, a resistor 42c, and a capacitor 42d. The low-pass filter 42 may be a primary RC low-pass filter including one resistor and a capacitor. Further, the low-pass filter 42 may be a third-order or higher RC low-pass filter.
The high pass filter 43 includes a capacitor 43a.

  The differential amplifier 50 includes resistors 51 and 52, an operational amplifier 53, a coupling capacitor 54, a bias circuit 55, and the like. The output terminal of the operational amplifier 53 is connected to the inverting input terminal of the operational amplifier 53 via the resistor 52, and negative feedback is applied to the operational amplifier 53. The output signal of the filter 40 (the output signal of the high pass filter 43) is input to the inverting input terminal of the operational amplifier 53 via the resistor 51, and the output signal of the band pass filter 30 is supplied to the operational amplifier via the coupling capacitor 54 and the bias circuit 55. 53 is input to the non-inverting input terminal. The coupling capacitor 54 removes a direct current component of the output signal of the band pass filter 30. The bias circuit 55 includes resistors 56 and 57 connected in series between the power supply voltage and the ground. The bias circuit 55 applies a bias voltage to the output signal of the bandpass filter 30 from which the DC component has been removed by the coupling capacitor 54, and raises the reference level of the output signal of the bandpass filter 30. Note that the coupling capacitor 54 and the bias circuit 55 may be omitted.

  The differential signal output by the differential amplifier 50 is a ripple component of the voltage signal converted by the current-voltage converter 10. Because the difference signal output by the differential amplifier 50 represents the difference between the output signal of the bandpass filter 30 and the output signal of the filter 40, the frequency of each component of the current signal of the motor 2 changes due to environmental changes. In addition, ripples included in the current signal of the motor 2 can be detected with high accuracy.

  As shown in FIGS. 1 and 7, the amplifier 60 inputs the differential signal (the output signal of the operational amplifier 53) output by the differential amplifier 50. The amplifier 60 amplifies the differential signal output by the differential amplifier 50 and outputs it to the waveform shaping unit 70. The amplifier 60 is, for example, a negative feedback amplifier.

  The waveform shaping unit 70 inputs the differential signal (the output signal of the operational amplifier 53) output from the differential amplifier 50 via the amplifier 60. The waveform shaping unit 70 shapes the waveform of the differential signal (the output signal of the amplifier 60) output by the differential amplifier 50 into a rectangular wave. Specifically, the waveform shaping unit 70 has a comparator, and the comparator compares the differential signal (the output signal of the amplifier 60) output by the differential amplifier 50 with a reference voltage, thereby allowing the differential amplifier 50 to The output differential signal (the output signal of the amplifier 60) is converted into a pulse signal. The waveform shaping unit 70 outputs a pulse signal shaped into a rectangular wave to the control unit 4. The control unit 4 receives the pulse signal output from the waveform shaping unit 70.

  The motor driver 6 drives the motor 2 in accordance with a command from the control unit 4. That is, when the motor driver 6 receives the start command and the rotation direction command from the control unit 4, the motor driver 6 starts the motor 2 in the rotation direction. When the motor driver 6 receives a stop command from the control unit 4, the motor driver 6 stops the motor 2.

  The A / D converter 7 is a voltage detection unit. That is, the A / D converter 7 detects the power supply voltage of the motor 2, converts the voltage signal into a digital signal, and outputs the digitized voltage data to the control unit 4. The control unit 4 inputs voltage data output by the A / D converter 7.

  The A / D converter 8 is a current detection unit. That is, the A / D converter 8 detects the current value of the motor 2, converts the current signal into a digital signal, and outputs the digitized current data to the control unit 4. Here, since the output signal of the current-voltage converter 10 represents the current of the motor 2, the A / D converter 8 converts the output signal of the current-voltage converter 10 into a digital signal and outputs it to the control unit 4. . The control unit 4 inputs current data output by the A / D converter 8.

  The control unit 4 is a computer having a CPU 4a, a RAM 4b, and the like. The CPU 4a performs various processes such as numerical calculation, information processing, and device control. The RAM 4b provides a work area as a temporary storage area to the CPU 4a.

  An input unit 9 c is connected to the control unit 4. The input unit 9c has a plurality of switches and the like. When the input unit 9c is operated by a user or the like, the input unit 9c outputs a signal corresponding to the operation content to the control unit 4, and the control unit 4 inputs the signal and sends a command corresponding to the signal to the motor driver. 6 is output.

  The storage unit 5 is connected to the control unit 4. The storage unit 5 is a readable / writable storage medium such as a nonvolatile memory or a hard disk. The storage unit 5 may be a single storage medium or a combination of a plurality of storage media. When the storage unit 5 is a combination of a plurality of storage media, any one of the storage media may be a ROM.

  The storage unit 5 stores initial position data 5A. The initial position data 5A indicates the initial position of the motor 2 before the motor 2 operates. Specifically, the initial position data 5A is represented by coordinates in the coordinate system shown in FIG. 2, and the coordinates representing the position of the motor 2 are represented by the number of pulses. Therefore, the initial position data 5A is expressed by the number of pulses of the pulse signal output by the extraction circuit 3 during the rotation of the motor 2 from the initial position to a predetermined origin position as shown in FIG. The initial position data 5A is a preset default value or a value written when the motor 2 has been operated before. If the initial position of the motor 2 is the origin position, the number of pulses representing the initial position data 5A is zero. The initial position data 5A is updated every time the motor 2 stops. Although the value of the initial position data 5A may be a value within the non-restraint range or the value of the lock position, the value of the initial position data 5A is within the constraint range (however, excluding the lock position and the constraint start position). Never become.

  The storage unit 5 stores constraint start position data 5B. The constraint start position data 5B represents the coordinates of the constraint start position in the coordinate system shown in FIG. Therefore, the constraint start position data 5B is represented by the number of pulses of the pulse signal output by the extraction circuit 3 during the rotation of the motor 2 from the constraint start position to a predetermined origin position as shown in FIG. .

  The storage unit 5 stores lock position data 5C. The lock position data 5C represents the coordinates of the lock position in the coordinate system shown in FIG. Therefore, the lock position data 5C is represented by the number of pulses of the pulse signal output by the extraction circuit 3 during the rotation of the motor 2 from the lock position to a predetermined origin position as shown in FIG.

  The values of the constraint start position data 5B and the lock position data 5C are values previously investigated through experiments and measurements.

  The storage unit 5 stores a program 5Z that can be read by the control unit 4. The control unit 4 reads the program 5Z and performs processing according to the program 5Z, or implements various functions by the program 5Z. The constraint start position data 5B and the lock position data 5C may be stored in the storage unit 5 separately from the program 5Z, or may be incorporated in the program 5Z. When the storage unit 5 is a combination of a plurality of storage media, the program 5Z may be stored in the ROM of the storage unit 5.

  The flow of processing of the control unit 4 based on the program 5Z will be described, and the operation of the motor control device 1 accompanying the processing of the control unit 4 will be described.

  When a predetermined activation condition is satisfied, the control unit 4 executes the activation process of the motor 2 (see FIG. 9). The predetermined activation condition is satisfied when, for example, the user turns on the activation switch of the input unit 9c, the activation sensor is turned on, or the processing (for example, sequence processing) executed by the control unit 4. For example, a predetermined condition is satisfied.

  First, the control unit 4 determines the rotation direction (forward rotation or reverse rotation) of the motor 2, and writes the rotation direction in the RAM or the storage unit 5 (step S11). The direction of rotation of the motor 2 is determined by a process executed by the control unit 4 or determined by an operation of the input unit 9c by the user. For example, if the user turns on the forward rotation start switch of the input unit 9c, the control unit 4 determines the rotation direction of the motor 2 to be forward rotation, and if the user turns on the reverse rotation start switch of the input unit 9c, The control unit 4 determines the direction of rotation of the motor 2 to be reverse.

  Next, the control unit 4 reads the initial position data 5 </ b> A stored in the storage unit 5. Then, the control unit 4 determines whether or not the value of the read initial position data 5A is equal to the value of the lock position data 5C (step S12).

  When the initial position of the motor 2 is not the lock position, the value of the initial position data 5A is different from the value of the lock position data 5C. In that case, the control unit 4 determines that the value of the initial position data 5A is not equal to the value of the lock position data 5C (step S12: NO). And the control part 4 starts the motor 2 in the direction determined by step S11 (step S16). That is, the control unit 4 outputs a rotation direction command according to the direction determined in step S <b> 11 to the motor driver 6 and outputs a start command to the motor driver 6. Upon receiving the rotation direction command and the start command, the motor driver 6 energizes the motor 2 to drive the motor 2 in the rotation direction. Thereby, the motor 2 rotates and the movable part is driven by the motor 2. If the control part 4 starts the motor 2, a starting process will be complete | finished. After starting the motor 2, the control unit 4 counts the number of pulses of the pulse signal based on the pulse signal input from the extraction circuit 3, calculates the rotation amount of the motor 2, and calculates the position (current position) of the motor 2. I do. Details will be described later (see FIG. 10).

  When the initial position of the motor 2 is one of the lock positions at both ends of the movable range, the value of the initial position data 5A corresponds to the value of the lock position data 5C. In that case, the control unit 4 determines that the value of the initial position data 5A is equal to the value of the lock position data 5C (step S12: YES). And the process of the control part 4 transfers to step S13. In step S13, the control unit 4 determines whether or not the direction determined in step S11 is a direction from the lock position toward the constraint start position (step S13).

  When the control unit 4 determines that the direction determined in step S11 is not the direction from the lock position to the constraint start position (step S13: NO), the control unit 4 does not start the motor 2 (step S18), and the startup process Ends. If the direction determined in step S11 is not the direction from the lock position to the restraint start position, the rotation direction of the motor 2 becomes the direction from the restraint start position to the lock position that is the initial position of the motor 2, and the transmission mechanism. Therefore, even if an electric current is supplied to the motor 2, the motor 2 does not rotate, and an overcurrent or the like may occur in the motor 2. However, since the control part 4 does not start the motor 2 (step S17), generation | occurrence | production of such an overcurrent etc. can be suppressed.

  When the control unit 4 determines that the direction determined in step S11 is the direction from the lock position toward the constraint start position (step S13: YES), the control unit 4 activates the motor 2 in the direction determined in step S11. (Step S14). That is, the control unit 4 outputs a rotation direction command according to the direction determined in step S <b> 11 to the motor driver 6 and outputs a start command to the motor driver 6. Upon receiving the rotation direction command and the start command, the motor driver 6 energizes the motor 2 to drive the motor 2 in the rotation direction. Thereby, the motor 2 rotates and the movable part is driven by the motor 2.

  After starting the motor 2, the control unit 4 counts the number of pulses of the pulse signal, calculates the rotation amount of the motor 2, and calculates the position (current position) of the motor 2 based on the pulse signal input from the extraction circuit 3. At the same time (see FIG. 10), the calculated position of the motor 2 is monitored (step S15). The controller 4 does not stop the motor 2 (step S15: NO, step S18) until the calculated position value of the motor 2 becomes equal to the value of the constraint start position data 5B (step S15: YES). The motor 2 is continuously operated (step S14). The user turns off the start switch of the input unit 9c or turns on the stop switch of the input unit 9c until the position value of the motor 2 calculated by the control unit 4 becomes equal to the value of the constraint start position data 5B. Even if the control unit 4 is used, the control unit 4 invalidates the operation and does not stop the motor 2 (step S18), and continues to operate the motor 2 (step S14).

  When the value of the position of the motor 2 calculated by the control unit 4 becomes a value corresponding to the constraint start position data 5B (step S15: YES), the control unit 4 ends the activation process. In addition, after the control part 4 starts the motor 2 (step S14, step S16), even if the control part 4 complete | finishes a starting process, unless the control part 4 stops the motor 2, the motor 2 continues. Rotate.

  During operation of the motor 2, the extraction circuit 3 extracts (detects) a ripple component from the current signal of the motor 2, and pulses the ripple component. Then, the extraction circuit 3 outputs a pulse signal obtained by pulsing the ripple component to the control unit 4.

  When the motor 2 is started, the control unit 4 counts the number of pulses of the pulse signal, calculates the rotation amount of the motor 2 and calculates the position of the motor 2 based on the pulse signal input from the extraction circuit 3. More specifically, the control unit 4 performs the processing shown in FIG. 10 to count the number of pulses of the pulse signal, calculate the rotation amount of the motor 2, and calculate the position of the motor 2.

The process shown in FIG. 10 will be specifically described.
The control unit 4 monitors the voltage data input from the A / D converter 7 and compares the voltage data with a predetermined threshold value (step S21). As described above, when the control unit 4 starts the motor 2 (step S16 or step S14), a current is passed through the motor 2. Therefore, the control unit 4 determines that the voltage data exceeds a predetermined threshold, and the motor 2 Is detected (step S21: Yes). And the control part 4 reads the initial position data 5A from the memory | storage part 5, and the process of the control part 4 transfers to step S22. The control unit 4 may monitor the current data input from the A / D converter 8, and the control unit 4 may compare the current data with a predetermined threshold (step S21). In this case, when a current is supplied to the motor 2, the control unit 4 determines that the current data has exceeded a predetermined threshold value, and detects energization / startup of the motor 2 (step S21: Yes).

  When the current is supplied to the motor 2, the control unit 4 counts the number of pulses of the pulse signal output by the extraction circuit 3, and calculates the rotation amount and position of the motor 2 (steps S22, S23, S24, S25). Specifically, first, the control unit 4 resets the count value N to zero (step S22). Thereafter, each time the pulse of the pulse signal output by the extraction circuit 3 is input (step S23: Yes), the control unit 4 updates the count value N to a value obtained by adding 1 to the count value N. At the same time (step S24), the updated count value N is added to the value of the read initial position data 5A, or the updated count value N is subtracted from the value of the read initial position data 5A (step S25). The control unit 4 determines the calculation in step S25 according to the direction determined in step S11. For example, when the rotation direction determined in step S11 is forward rotation, the control unit 4 performs addition in step S25, and when the rotation direction determined in step S11 is reverse rotation, the control unit 4 Subtracts in step S25. Of course, the relationship between the direction of rotation and the calculation may be reversed.

  The count value N updated in step S24 is the number of pulses counted by the control unit 4. The number of pulses (count value N) counted by the control unit 4 represents the amount of rotation from the initial position to the current position in the coordinate system of the motor 2 (see FIG. 2). The difference or sum obtained in step S25 represents the current position of the motor 2 at the time when the pulse is input. As described above, if the difference or sum calculated by the control unit 4 in step S25 is a value corresponding to the constraint start position data 5B (step S15: YES), the control unit 4 ends the activation process, and the control unit 4 If the difference or sum calculated in step S25 is not a value corresponding to the constraint start position data 5B (step S15: NO), the control unit 4 continues the starting process and prohibits the motor 2 from stopping (step S18). ).

  The control part 4 repeats the process of step S23-step S26 until it detects the interruption | blocking of the electric current of the motor 2 (step S26: No). Specifically, the control unit 4 compares the voltage data input from the A / D converter 7 with a predetermined threshold after the process of step S25 (step S26). If the current of the motor 2 is not interrupted, the control unit 4 determines that the voltage data exceeds a predetermined threshold (step S26: No), the process of the control unit 4 returns to step S23, and the control unit 4 4 performs the processing of step S23 to step S25 again. In step S26, the control unit 4 may compare the current data input from the A / D converter 8 with a predetermined threshold (step S26). In this case, if the current of the motor 2 is not interrupted, the control unit 4 determines that the current data has exceeded a predetermined threshold (step S26: No), and the control unit 4 performs the processing of step S23 to step S25 again. .

  If a predetermined stop condition is satisfied while the control unit 4 is executing the process shown in FIG. 10, the control unit 4 executes a stop process (see FIG. 11) of the motor 2. The predetermined stop condition is, for example, that a user turns on a stop switch of the input unit 9c, a user turns off a start switch of the input unit 9c, or a process executed by the control unit 4 (for example, a sequence process). ), A predetermined condition is satisfied, and the difference or sum obtained in step S25 is a predetermined value.

  First, the control unit 4 determines whether or not the difference or the sum (position of the motor 2) calculated in step S25 is within the unconstrained range immediately after the stop process is started (step S31). Specifically, the control unit 4 compares the difference or sum calculated in step S25 with the value of the constraint start position data 5B (step S31).

  As a result of the comparison, when the control unit 4 determines that the difference or the sum (position of the motor 2) calculated in step S25 is within the unconstrained range immediately after the start of the stop process (step S31: YES), the control unit 4 Outputs a stop command to the motor driver 6 (step S41). If it does so, the motor driver 6 which received the stop command will interrupt | block the electricity supply of the motor 2, and the motor 2 will stop. The stop position of the motor 2 is between one restraint start position and the other restraint start position. Since the current of the motor 2 is interrupted by the motor driver 6, the control unit 4 determines that the voltage data input from the A / D converter 7 has fallen below a predetermined threshold (step S26: Yes). The process shown in FIG. When the control unit 4 compares the current data input from the A / D converter 8 with a predetermined threshold (step S26), when the current of the motor 2 is interrupted, the control unit 4 causes the current data to fall below the predetermined threshold. 90 (step S26: Yes), the control unit 4 ends the process shown in FIG.

  Next, the control unit 4 writes the difference or sum calculated in step S25 immediately after the stop process is started in the storage unit 5 (step S42). Specifically, the control unit 4 rewrites the value of the initial position data 5A stored in the storage unit 5 with the difference or sum obtained in step S25 immediately after the start of the stop process (step S42). Thereafter, the control unit 4 ends the stop process.

As a result of the comparison in step S31, when the control unit 4 determines that the difference or sum (position of the motor 2) calculated in step S25 is not within the unconstrained range (step S31: NO)
), The process of the control unit 4 proceeds to step S32. In step 32, the control unit 4 determines whether or not the direction determined in step S11 is a direction from the lock position toward the constraint start position (step S32).

  When the control unit 4 determines that the direction determined in step S11 is the direction from the lock position toward the constraint start position (step S32: YES), the control unit 4 does not stop the motor 2 (step S37), and the motor 2 is operated continuously. If the motor 2 is rotating when the value of the initial position data 5A before the motor 2 is started is equal to the value of the lock position data 5C (step S12 (YES), step S13 (YES) shown in FIG. 9). , See step S14), the process of the control unit 4 proceeds from step S32 to step S37.

  Since the motor 2 continues to rotate (see step S37), the control unit 4 repeatedly executes the processes in steps S23 to S26 shown in FIG. Therefore, the control unit 4 calculates the position of the motor 2 every time the pulse of the pulse signal output by the extraction circuit 3 is input (step S25). Then, the control unit 4 does not stop the motor 2 (step S38: NO, until the value of the position of the motor 2 calculated in step S25 becomes equal to the value of the constraint start position data 5B (step S38: YES). Step S37), the motor 2 is continuously operated.

  When the rotation of the motor 2 continues, if the position value of the motor 2 calculated by the control unit 4 becomes equal to the value of the constraint start position data 5B (step S38: YES), the control unit 4 determines that the motor driver A stop command is output to 6 (step S39). If it does so, the motor driver 6 which received the stop command will interrupt | block the electricity supply of the motor 2, and the motor 2 will stop. The stop position of the motor 2 is a restraint start position. Since the current of the motor 2 is interrupted by the motor driver 6, the control unit 4 determines that the voltage data input from the A / D converter 7 has fallen below a predetermined threshold (step S26: Yes). The process shown in FIG.

  Next, the control part 4 writes the difference or sum calculated | required in the last step S25 in the memory | storage part 5 when repeating the process of step S23-step S26 shown in FIG. 9 (step S40). Specifically, the control unit 4 rewrites the value of the initial position data 5A stored in the storage unit 5 to the difference or sum obtained in the last step S25 (step S40). The rewritten value of the initial position data 5A is equal to the value of the constraint start position data 5B or approximate to the value of the constraint start position data 5B. Thereafter, the control unit 4 ends the stop process. In step S40, the control unit 4 may rewrite the value of the initial position data 5A stored in the storage unit 5 to the value of the constraint start position data 5B.

  In the determination of step S32, when the control unit 4 determines that the direction determined in step S11 is not the direction from the lock position toward the constraint start position (step S32: NO), the process of the control unit 4 proceeds to step S33. When the position of the motor 2 moves from the unconstrained range to the restrained range beyond the restraint start position, the process of the control unit 4 proceeds to step S33.

  In step S33, the control unit 4 monitors the current data input from the A / D converter 8, and compares the current data with a predetermined value (step S33). The predetermined value is obtained by preliminarily measuring the current flowing through the motor 2 by applying a constant voltage to the motor 2 while restraining the motor 2. That is, the predetermined value is a current value serving as a reference for determining whether or not the motor 2 is in a restrained state.

  If the motor 2 is rotating from the restraint start position toward the lock position within the restraint range, the motor 2 is not restrained, so the current flowing through the motor 2 does not exceed a predetermined value. It is determined that the current data input from the / D converter 8 is less than a predetermined value (step S33: NO). In that case, the control unit 4 continues to operate the motor 2 without stopping the motor 2 (step S34), and also continues to monitor the current data input from the A / D converter 8 (step S33).

  When the rotation of the motor 2 continues and the play or the like of the transmission mechanism is tightened, the motor 2 is restrained at the lock position. If it does so, the electric current which flows into the motor 2 will become more than a predetermined threshold value. Therefore, the control unit 4 determines that the current data input from the A / D converter 8 is greater than or equal to a predetermined value (step S33: NO). The control unit 4 outputs a stop command to the motor driver 6 (step S35). If it does so, the motor driver 6 which received the stop command will interrupt | block the electricity supply of the motor 2, and the motor 2 will stop. The stop position of the motor 2 is the lock position.

  After stopping the motor 2, the control unit 4 rewrites the value of the initial position data 5A stored in the storage unit 5 to the value of the lock position data 5C (step S36). Thereafter, the control unit 4 ends the stop process.

  What has been described above is the description of the operation of the motor control device 1. The motor control device 1 shown in FIG. 1 is used for a vehicle seat device, for example. The vehicle seat device includes the motor control device 1 shown in FIG. 1 and the seat body 90 shown in FIG. 12, and the movable portion of the seat body 90 is driven by the motor 2.

  The number of movable parts of the seat body 90 and the number of motors 2 are preferably the same. When there are a plurality of motors 2, a motor driver 6 and an extraction circuit 3 are provided for each motor 2, and the control unit 4 and The storage unit 5 is common to all the motors 2. When there are a plurality of motors 2, initial position data 5 </ b> A, constraint start position data 5 </ b> B, and lock position data 5 </ b> C are stored in the storage unit 5 for each motor 2. When the number of motors 2 is plural, the number of motor drivers 6 and extraction circuits 3 may be one. In that case, a relay circuit is provided, and the relay circuit selects any one of the plurality of motors 2 in accordance with a command from the control unit 4. The motor 2 selected by the relay circuit is connected to the extraction circuit 3 and the motor driver 6, and the others are disconnected from the extraction circuit 3 and the motor driver 6.

  The sheet body 90 will be specifically described. The seat body 90 includes a rail 91, a seat bottom 92, a backrest 93, a headrest 94, an armrest 95, a legrest 96, and the like.

  The seat bottom 92 is mounted on the rail 91, the seat bottom 92 is provided so as to be movable in the front-rear direction by the rail 91, and the motor 2 drives the seat bottom 92 in the front-rear direction. The front part of the seat bottom 92 is provided to be movable up and down, and another motor 2 drives the front part of the seat bottom 92 in the vertical direction. The rear part of the seat bottom 92 is provided so as to be movable up and down, and another motor 2 drives the rear part of the seat bottom 92 in the vertical direction. The backrest 93 is rotatably connected to the rear end portion of the seat bottom 92 by a reclining mechanism, and another motor 2 raises and lowers the backrest 93 with respect to the seat bottom 92. The headrest 94 is connected to the upper end of the backrest 93 so as to be able to move up and down and rotate, and another motor 2 drives the headrest 94 in the vertical direction, and another motor 2 undulates the headrest 94 back and forth. The armrest 95 is rotatably connected to the side surface of the backrest 93, and another motor 2 drives the armrest 95 from the horizontal state to the vertical state and vice versa. A legrest 96 is rotatably connected to the front end portion of the seat bottom 92, and another motor 2 drives the legrest 96 from a flipped state to a suspended state or vice versa.

  A movable range is set in any movable part of the sheet main body 90, and stoppers are provided at both ends of the movable range.

The embodiment of the present invention has the following effects.
(1) When the position of the motor 2 is within the constraint range during the operation of the motor 2 (see step S31 (NO)), the motor 2 does not stop even if a predetermined stop condition is satisfied. The motor 2 continues to rotate (see step S34). Thereafter, when the motor 2 moves to the lock position and the current of the motor 2 increases (see step S33 (YES)), the motor 2 stops. Therefore, the motor 2 does not stop within the restraint range but stops at the lock position. Since the control unit 4 updates the value of the initial position data 5A to the value of the lock position data 5C (see step S36), even when a cumulative error occurs in the position of the motor 2 calculated by the control unit 4, The error is eliminated.
(2) If the position of the motor 2 is within the restraint range and the rotation direction of the motor 2 is from the restraint start position toward the lock position, the motor 2 rotates at an extremely low speed. The pulse is not generated accurately in the pulse signal. Even in such a case, the motor 2 does not stop within the restraint range but stops at the lock position (see step S35), and the position of the motor 2 calculated by the control unit 4 is further reset, and the value of the initial position data 5A Is updated to the value of the lock position data 5C. Therefore, the controller 4 can accurately calculate the position of the motor 2 even if a pulse is not accurately generated in the pulse signal output from the extraction circuit 3.
(3) When the motor 2 is restarted after the motor 2 is stopped at the lock position (see step S14), the value of the position of the motor 2 calculated by the control unit 4 is equal to the value of the constraint start position data 5B. Stopping the motor 2 is prohibited (see Step S14, Step S15, Step S18, Step S38, Step S37). Therefore, the motor 2 does not stop within the restricted range.
(4) The initial position, the constraint start position and the lock position are defined by a coordinate system representing the position of the motor 2 (see FIG. 2), and the initial position data, the constraint start position data and the lock position data indicate the number of pulses of the motor 2 position. It expresses with. Therefore, the control unit 4 does not control the motor 2 based on the coordinate system expressing the position of the movable unit 99 but controls the motor 2 based on the coordinate system expressing the position of the motor 2. (See FIG. 2). Therefore, when the movable part 99 abuts against the stopper 98 and the movable part 99 is restrained, the position control of the motor 2 is performed in consideration of further rotation of the motor 2.
(5) Since the high cut-off frequency fc2 of the filter 40 is set lower than the frequency of the ripple component in the circuit design of the filter 40, the ripple component can be removed by the filter 40.
(6) The differential amplifier 50 outputs the output signal of the bandpass filter 30 (the voltage signal converted by the current-voltage converter 10 from which the DC component and the high-frequency noise component are removed) and the output signal of the filter 40. The difference between the voltage signals converted by the current-voltage converter 10 from which the DC component, the high-frequency noise component, the ripple component, etc. are removed is taken and output as a difference signal. Therefore, the output signal of the differential amplifier 50 is a ripple component in the voltage signal converted by the current-voltage converter 10. Because the output signal of the differential amplifier 50 is a differential signal, even if the frequency of each component of the current signal of the motor 2 fluctuates due to environmental changes, the ripple component is accurately extracted, Ripple can be detected with high accuracy.
(7) Of the frequency characteristics shown in FIG. 5, the output of the differential amplifier 50 can be obtained even if the frequency of the ripple component fluctuates due to temperature change because the slope portion in the region higher than the high cutoff frequency fc2 is used. The signal is accurately extracted as a ripple component.
(8) Since the ripple component is extracted by the filter 40 and the differential amplifier 50 using the frequency characteristics of the filter 40, it is not necessary to use a variable cutoff frequency filter for the filter 40. Therefore, the cost of the filter 40 can be reduced.
(9) Since the extraction circuit 3 is not a closed loop circuit such as a feedback control circuit, it is possible to accurately detect ripples even if the frequency of each component of the current signal of the motor 2 changes transiently or rapidly. .
(10) Since the filter 40 is a filter including resistors 41b, 41d, 41a, and 41c and capacitors 41a, 41c, 41b, 41d, and 43a, the configuration of the filter 40 is simple, and the cost increase of the filter 40 is suppressed. Can do.
(11) Since the ripple component is extracted by the filter 40 and the differential amplifier 50 using the frequency characteristics of the filter 40, it is not necessary to use a variable cutoff frequency filter for the high-pass filter 20 or the band-pass filter 30. Therefore, the cost increase of the high pass filter 20 and the band pass filter 30 can be suppressed.
(12) Since the DC component of the voltage signal converted by the current-voltage converter 10 is removed by the high-pass filter 20, the processing of the band-pass filter 30, the filter 40 and the differential amplifier 50 subsequent to the high-pass filter 20 is performed. Exactly done.
(13) Since the component outside the predetermined frequency band of the voltage signal converted by the current-voltage converter 10 is attenuated by the band-pass filter 30, the processing of the filter 40 and the differential amplifier 50 subsequent to the band-pass filter 30 is performed. Exactly done.

[Modification]
The embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention. Hereinafter, modified examples will be described. The following modifications may be combined as much as possible.

[Modification 1]
In step S22 described above, the control unit 4 may set the count value N in the initial position data 5A instead of resetting the count value N to zero. In this case, the process in step S25 is omitted. Further, in step S24, the control unit 4 updates the count value N by adding or subtracting 1 to the count value N every time the pulse of the pulse signal output by the extraction circuit 3 is input. The control unit 4 determines the calculations in step S24 and step S49 according to the direction determined in step S11. For example, when the rotation direction determined in step S11 is normal rotation, the control unit 4 performs addition in step S24, and when the rotation direction determined in step S11 is reverse rotation, the control unit 4 Performs subtraction in step S24. Of course, the relationship between the direction of rotation and the calculation may be reversed.

  The count value N updated in step S24 represents the current position of the motor 2, and represents the distance from the origin position to the current position with the origin position as a reference in the number of pulses.

[Modification 2]
The extraction circuit 3 is an example, and is not limited to the circuit of the above-described embodiment. For example, the filter 40 and the differential amplifier 50 may be omitted. In this case, a switched capacitor filter is provided after the band-pass filter 30 and before the amplifier 60 so that the ripple component can be accurately extracted even if the frequency of the ripple component changes. preferable. Even when the cutoff frequency of the switched capacitor filter is variable and the frequency of the ripple component or the low frequency component changes, the switched capacitor filter attenuates the low frequency component and passes the ripple component.

[Modification 3]
In the circuit design of the filter 40, the low cut-off frequency fc1 of the filter 40 shown in FIG. 6 is set to be higher than the frequency of the ripple component (for example, the frequency at normal temperature) while taking into account the fluctuation of the frequency of the ripple component due to temperature change. Has been. Therefore, the filter 40 attenuates the ripple component of the voltage signal (the output signal of the bandpass filter 30) converted by the current-voltage converter 10 higher than the high-frequency component (the high-frequency component has a higher frequency than the ripple component). Decay at a rate. That is, the filter 40 removes the ripple component more efficiently than the high frequency component. Therefore, the filter 40 outputs a signal from which the ripple component has been removed to the differential amplifier 50.
In this case, the current signal of the motor 2 and the input signals of the filter 40 and the differential amplifier 50 are obtained by superimposing a ripple component and a high frequency component having a higher frequency than the ripple component.

[Modification 4]
The filter 40 may be a low-pass filter having frequency characteristics as shown in FIG. 13 instead of the band-pass filter. The filter 40 passes the component below the cutoff frequency fc3 among the voltage signal (the output signal of the bandpass filter 30) converted by the current-voltage converter 10, and attenuates the component exceeding the cutoff frequency fc3. Specifically, in a high frequency region exceeding the cut-off frequency fc3, the filter 40 decreases the attenuation rate as the frequency of the component included in the voltage signal (the output signal of the bandpass filter 30) converted by the current-voltage converter 10 decreases. Is attenuated so that the voltage signal converted by the current-voltage converter 10 (the output signal of the bandpass filter 30) is attenuated.

  In the circuit design of the filter 40, the cut-off frequency fc3 of the filter 40 shown in FIG. 13 is set to be lower than the frequency of the ripple component (for example, the frequency at normal temperature) while taking into account fluctuations in the frequency of the ripple component due to temperature changes. ing. Therefore, the filter 40 has a ripple component in the voltage signal (the output signal of the band pass filter 30) converted by the current-voltage converter 10 that is lower in frequency than the low frequency component (the frequency of the low frequency component is lower than that of the ripple component). Attenuate with high attenuation factor. That is, the filter 40 removes the ripple component more efficiently than the low frequency component. Therefore, the filter 40 outputs a signal from which the ripple component has been removed to the differential amplifier 50.

In this case, the current signal of the motor 2 and the input signal of the filter 40 and the differential amplifier 50 are obtained by superimposing a ripple component and a low frequency component having a frequency lower than that of the ripple component.
When the filter 40 is a low-pass filter, the high-pass filters 41 and 43 shown in FIG. 7 are omitted, the output of the band-pass filter 30 is connected to the input of the low-pass filter 42, and the output of the low-pass filter 42 is connected via the resistor 51. The inverting input terminal of the operational amplifier 53 is connected.

[Modification 5]
The filter 40 may be a high-pass filter having a frequency characteristic as shown in FIG. 14 instead of the band-pass filter. The filter 40 passes a component having a cutoff frequency fc4 or higher in the voltage signal (the output signal of the bandpass filter 30) converted by the current-voltage converter 10, and attenuates a component lower than the cutoff frequency fc4. Specifically, in the low frequency region below the cut-off frequency fc4, the filter 40 attenuates as the frequency of the component included in the voltage signal (the output signal of the bandpass filter 30) converted by the current-voltage converter 10 decreases. The voltage signal (the output signal of the bandpass filter 30) converted by the current-voltage converter 10 is attenuated so that the rate becomes higher.

In the circuit design of the filter 40, the cut-off frequency fc4 of the filter 40 shown in FIG. 14 is set to be higher than the frequency of the ripple component (for example, the frequency at normal temperature) while taking into account fluctuations in the frequency of the ripple component due to temperature changes. ing. Therefore, the filter 40 attenuates the ripple component of the voltage signal (the output signal of the bandpass filter 30) converted by the current-voltage converter 10 higher than the high-frequency component (the high-frequency component has a higher frequency than the ripple component). Decay at a rate. That is, the filter 40 removes the ripple component more efficiently than the high frequency component. Therefore, the filter 40 outputs a signal from which the ripple component has been removed to the differential amplifier 50.
When the filter 40 is a high pass filter, the low pass filter 42 shown in FIG. 7 is omitted, and the output of the band pass filter 30 is connected to the input of the high pass filter 41.

[Modification 6]
The filter 40 may be a band stop filter instead of a band pass filter.

[Modification 7]
One or both of the high pass filter 20 and the band pass filter 30 may be omitted. When the high-pass filter 20 is omitted, the output of the current-voltage converter 10 is connected to the input of the band-pass filter 30. When the band pass filter 30 is omitted, the output of the high pass filter 20 is connected to the input of the filter 40 and the input of the differential amplifier 50. When both the high-pass filter 20 and the band-pass filter 30 are omitted, the output of the current-voltage converter 10 is connected to the input of the filter 40 and the input of the differential amplifier 50.

[Modification 8]
The motor control device 1 is incorporated in an electric door mirror device, and a movable part of the electric door mirror device (for example, a storage mechanism that stores and unfolds the mirror housing with respect to the door, a tilt mechanism that swings the mirror up and down with respect to the mirror housing, a mirror) A pan mechanism that swings the mirror to the left and right with respect to the housing may be driven by the motor 2 of the motor control device 1. The motor control device 1 may be incorporated in the power window device, and the movable portion (for example, window regulator) of the power window device may be driven by the motor 2.

[Modification 9]
The filter 40 may use an operational amplifier (for example, a negative feedback low-pass filter, a positive feedback low-pass filter, a multiple negative feedback band-pass filter, or a multiple positive feedback band-pass filter).

DESCRIPTION OF SYMBOLS 1 Motor control apparatus 2 Motor 3 Extraction circuit 4 Control part 5 Memory | storage part 5A Initial position data 5B Restriction start position data 5C Lock position data 8 A / D converter (current detection part)
98 Stopper 99 Movable part

Claims (6)

A motor that drives a movable part movable between both ends of the movable range and generates a periodic ripple in the current signal when operated;
An extraction circuit that extracts a ripple component from the current signal of the motor and outputs a pulse signal obtained by pulsing the ripple component;
A current detector for detecting the current of the motor;
A controller that controls the motor by inputting the data of the current detected by the current detector and the pulse signal.
Initial position data representing the initial position before operation of the motor by the number of pulses from the initial position to a predetermined origin position, and the movable part moves from the movable range to the end and the motor further rotates. Restriction start position data representing the restriction start position of the motor in terms of the number of pulses from the restriction start position to the origin position, and the movable part is positioned at the end of the movable range and the motor is more than that A storage unit that stores lock position data in which the lock position of the motor that is restrained without being rotated is represented by the number of pulses from the lock position to the origin position; and
The control unit is
A starting process for starting the motor;
Each time a pulse of the pulse signal is input after the start-up process, the number of pulses generated in the pulse signal after the start-up process is counted, and the counted number of pulses is added to the value of the initial position data, or the counted pulse A counting process for subtracting a number from the value of the initial position data;
A determination process for determining whether or not the position of the motor is between the constraint start positions by comparing the difference or sum calculated in the counting process after the activation process with the value of the constraint start position data;
When it is determined in the determination process that the position of the motor is not between the restraint start positions, the rotation of the motor is continued until the current data input from the current detection unit becomes a predetermined value or more, and the current detection unit A stop process for stopping the motor when the current data input from is over a predetermined value;
A motor control device further executing, after the stop process, an update process for rewriting the initial position data stored in the storage unit to a value of the lock position data. The control unit is
A second determination process for determining whether the value of the initial position data is equal to the value of the lock position data;
When it is determined in the second determination process that the value of the initial position data is equal to the value of the lock position data, the difference or sum calculated in the counting process after execution of the activation process is the value of the constraint start position data The motor control device according to claim 1, further comprising: a prohibiting process that prohibits the motor from being stopped until equal to.   The said control part further performs the 2nd stop process which stops the said motor, when it determines in the said determination process that the position of the said motor is between the said restraint start positions. Motor control device.   3. The motor control device according to claim 2, wherein when the control unit determines in the second determination process that the value of the initial position data is not equal to the value of the lock position data, the motor control device according to claim 2.   5. The motor control device according to claim 1, wherein the control unit executes the determination process when a predetermined stop condition is satisfied after the start process. 6. A motor control device according to any one of claims 1 to 5;
A vehicle seat device comprising: a seat body having the movable portion driven by the motor.

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